A Case of Klinefelter's Syndrome Associated with Rheumatoid Arthritis

Klinefelter's syndrome (KFS) is a gonosomal aberration disease that occurs in males, and is characterized by 47, XXY karyotype, hypogonadism and a lack of secondary sexual characteristics. A potential link between this hormonally deficient syndrome and autoimmune disease, particularly systemic lupus erythematosus (SLE), has been reported. On the other hand, KFS is rarely reported to be accompanied by rheumatoid arthritis (RA), and there are no Korean cases reported. We report the first Korean case of a KFS patient with sero-positive RA and discuss the role of the pathogenesis of RA with KFS.